Shipping drum



y 1963 o. J. VAN LEER ETAL 3,088626 CHRISTIAN RAGETTLI red States Thepresent invention relates to shipping drums, and, more particularly, toa rneans -for reinforcing the end of the drum against harmonieoscillation.

During recent years the demand for relatively lightweight shjpping drumscapable of withstanding the rigors of transportation has beenincreasing. Sueh drums, in the standard fiftyfive gallon size, aregenerally filled with a liquid material and transported via truck and/orrailroad cars to either a point of consumption or storage.

long with increased demand for such drums has been the desire to reducethe costs of manufiacture and transportation of the drums. In an effortto overcome the weight and oost problems, manufacturers have followed atrend to thinner and lighter metal.

Shippers have been continuously plagued by drum failures resulting frommetal zfatigue, particularly in tbat regon where the end member of thedrum meets the side walls known as the "knuckle radius. Such metalfatigue and consequent drum ailure, bas been found to result from thelocalized bending -accompanying the harmonie oscillations which arereduced in the end member of a filled drum during transport. T heproblem of drum-head harmonie oseillation has become increasingly vexingwith the use of thinner and lighter metal stock.

The fatigue and -resulting fracture becomes a particularly seriousproblem When transportingh azardous material such as gasoline, corrosiveliquid chemicals, and the like. Effor'os have been made to reinforcet-he drum ends,- for example, by going to special contours or by using aheavier gauge material. However, special oontours have not beenparticularly satisfactory, and any =appreciable increase in thethickness of the metal =adds to the cost and dead weight.

Accordingly, it is an object of this invention to provide a drum h=avinga renforced flat end member which is stronger than the end membersconventionally employed. It is a more specific object to providereinforcing means capable of minimizing drum-head harmonie oscillationsduring transportation of the drum. It isarelated object to provide anevel reinforeing element capable of" minimizing harmonie oscillationand reducing vibrational flexure of a drum end member, which flexureresults in metal fatigue.

It is another object to provide -an end member which facilitatesstaeking the drums in a straight stack and which makes it unnecessaryfor care to be exercised in alinng the drums with one anotherseam-to-searn. Cumulative cocking error is thereby minimized, neatst-acking is assured and risk of toppling is avoided.

It is a further object to provide a novel reinforcing means for use withshipping drum end members and which at the same time serves todistribute sharply concentrated forces over a wide area, thus reducingthe unit stress to a level below that which will eause severe denting orpuncturing. It is, therefore, an object to provide a drum having abottom capable of resisting puncturing When the. drums are stacked onrough or uneven storage spaces, for example, in primitive oil producingareas.

It is another object to provide -an improved shipping drum. end memberand reinforcing means therefor so as to allow the drum to be constructedfrom a lghter gauge ateit ice metal than Would otherwise be used, with aconsequent saving in both oost and dead Weght.

These and -other objects and -advantages of this invention will becomeapparent upon reading the attaehed detailed deseription and uponreference to the drawings in which:

FIGURE 1 is a perspective view of an assembled shipping drum embodyingthe inven-ton;

FIG. 2 is an enlarged cross sectioi1 through one of the reinforeing cupmembers employed in accordance with the invention;

FIG. 3 is a section taken along the line 33 in FIG. 1 to bring out theheight relationshipg according to the preferred embodiment of thisinvention;

FIG. 4 is -an end view of a shpping drum discldsing a modified form of areinforcing member; and 7 FIG. 5 is a section taken alongthe lne 5+5 inFIG. 4.

While this invention has been described in connection with a preferredembodment, it will be understood that it is not intended to be iimitedto this specifie embodiment, but rat-her to cover such equivalent andalterhative corrstruction as may be included withn the spirit and scopeof the appended claims.

Referring to the drawing there is illustrated in FIG. 1 a shipping drum11) having a cylindrical wall or body 11 which includes two or morespaced beads 12 to strengthen the drum and to facilitate rolling it.Secured to the bot tom of the drum is an end member 15 which is joinedto the drum wall by a curled sea=m or chime 16. Concentration of themetal at the seam renforces the drum was a whole and permits it to betipped =or -rolled on edge. Moreover, the seam 16 serves to transmitedgewise force to the drum wall When the drums are stacked in alinment,seam-to-seam'.

To form the seam the end member 15 isin the form of -a flat disk 13having an upst-anding annular bead 20 (FIG. 3) about its periphery anddefining an annular charinel 21 which engages one end of the cylindricaldrum wall 11. It will be understood that after the drum wall 11 isseated in place within the channel 21, and as a subsequent manufacturingstep, the two members are curled to'geth'er in overlapping relation toform the end seam 16. The flat central disk 18 is recessed with respectto the seam by"a predetermined depth -as indicated at d in FIG. 3.

It will be understood that When a shipping drum as hereinbeforedescribed is being transportecl in the'filled condition, the bob-hingmotion of the transportng vehicle is transmitted to the liquid withinthedrum. The liquid and resilient end member of the drum together form aresonant, oscillating system with the result th-at destructive harmonieoscillation is built u-p inthe drurnend member, even thoug-h theinitiating vibraton is of low amplitude. When the oscillaton continuesover a period of days the result is fatigue and fraeture, oftenwit-hleakageof the entire contents. The time required to produce thi'sdestructive effect in a shippingdnum is dependent on various factorssuch as the periodand ar1'uplitudeof the initiating vibration, thenature andhardness of the met'al as Well as its thiekness, and thedensity of the liquid being transported. Some understanding of theforces nvolved may be gained from the fact that a s hipping drum filledwith water weighs approximately 500 pounds, the water beingincompressible and co'nfinedso' that its full efiect is exerted on thethin bottom member.

In aecordance with one ofthe irriportant aspectsofthis in face-to-facecontact over a substantial porton of the surface for inhibitng flexionalvibration. In the preferred embodiment of this invention, three suchreinforcing elements of channel cross section, here in tl1e form of cups31, 32 and 33, have been employed and are aflixed to the end member in atwo dimensional, triangular pat tern, as illustrated in FIG. 1. Ofcourse, while three Such cups have been shown as afixed to the endmember 15 in a triangular configuration, it will be understood that theparticular number of reinforcing elements employed and the particularpattern in which they are arrayed may vary without departing from theinvention. Moreover, the reinforcing elements may take other forms asillustrated in -FIG. 4 and to be discussed at a later point. While wehave disclosed panticular forms of reinforcing members and particularconfigurations, it will be understood that the forms and configurationsmay be varied while still falling within the true scope and spirit ofthis invention.

Referring to FIG. 2, and in accordance With the preferred embodiment ofthis invention, a typical cup 31 has been illustrated. It will be notedthat the cup 31 is of channel-like cross section having a base 35, andan up standing wall 36 which terminates in an outwardly extending fiange37. The height of the cup indicated at a' is preferably constant overthe entire area thereof and preferably equal to the height of theupstanding bead 20. Thus, the bottom portion 35 of the cup and the baseof the bead 16 define a substantially flush supporting surface for thedrum. 'I'he cup flanges 37, which extend over a substantial area of theflat disk portion 18 of the end member 15 in face-to-face contacttherewith, are spot welded at spaced intervals to the bottom surface 19thereof as, for example, indicated at 38 in FIG. 3.

While this invention has been descrbed in connection With a shippingdrum having reinforcing elements secured to only the bottom end memberthereof, it will be understood that the reinforcing elements may also beseeured to the top end member in a similar manner, thus allowing thedrums to be stacked one upon another either upright or in invertedposition.

In effect, the reinforcing cups form a plurality of boxlike protrusionswhich are rigidly secured to the bottom surface 19 of the end member.Analysis shows that the reinforcing elements serve several distinctfunctions.

First of all, the elements 3 1-33 serve as suppor-ting pedestals so thatthe weight of the contents is not diaphragm supported but rathertransmitted directly to the underlying surface. But even when thereinforcing members are not in actual contact With a supporting surfacethe arrangement is beneficial since the extensive facetoface contactbetween the end member and the reinforcing elements, and the rgid natureof the latter, prevent the end member from acting as a vibratingdiaphragm. Not only is the end member rigidfied but the period ofnatural vibration is changed so that it is no longer resonant undertransport conditions.

Moreover, shipping drums employing reinforcing elements ofchannel-shaped cross section may be stacked upon one another tosubstantial heights without subjecting the bottom of the lowermost drumto localized puncturing stress resulting from irregularities andprojections on the supporting surface. Such localized pressures cancause denting, weakening of the metal, or actual puncturing wheneXer-ted against the bottom of a drum that is not equipped Withreinforcing means of the type disclosed in this invention. However, byuse of this invention, the bottom portions 35 of the cups in eifectserve as a double bottom and any concentrated pressure appled to one ofthe cups is distributed over a substantial area of the end member.Finally, the bottom portions 35 of the cups and the end seam 16 of thedrum provide a substantially flush supporting surface which will enablethe drums to be stacked one upon another without having to aline thedrums seam-to-seam. Even when the drums are slightly offset from oneanother, the cups tend to keep the drums square and prevent them fromcocking. Where the 4 drums are stacked in a plurality of tiers thecocking error tends to be cumulative and thus creates a toppling hazard.With the use of the present invention, the danger of toppling isminimized and neat and safe stacks are provided.

While the preferred embodimeut of this inventon contemplates the use ofa plurality of fianged hollow cups, it will be understood that etherforms of reinforcing members may be used. For example, a single largecup may be used as set forth in FIGS. 4 and 5. Here the cup, indicatedat 40, is axially centered With respect to the drum bottom 15a and has adiameter which is approximately one-third that of the drum itself.Encircling the cup is a flange 4-1 having a series of spot Welds 42 tothe drum bottom. Preferably the cup is dished inwardly at the center forface-to-face contact over a limited area 43. This adds to the rigidityproviding support about a circle M and enabling thinner metal -to beused than Would otherwise be possible. The advantages of the reinforcingmember 40 are substantially the Same as is the earlier embodiment. Wherethe drums are stacked, and assuming that the disclosed reinforcement isused top and bottom, direct contact between the opposed reinforcingmembers is assured. Even thougl1 the drums may not be perfectlycentered, the circles 44 are certain to intersect in direct supportingengagement. With regard to the bottom drum in the stack, this need notbe seated on a perfectly flat supporting surface to get the desiredsupporting eiect; if only a portion of the circle 44 touches that isenough to prevent harmonic vibration. If, as may occur under somecircumstances, part of the renforcing member is supported, the memberstill acts to rigidify the bottom to dampen any vibrations therein andthereby to efiectively inhibit any tendency toward oscillation. Thus,fatigue, and resulting rupture, are prevented under a1l pOS- sibleconditions of use.

While the invention has been described in connection With preferredreinforcing elements having a height substantially equal to the heightof the upstanding bead 20, there-by providing a substantially flushsupporting surface, it will be understood that the supporting elementscould have a slightly lesser height without departing from certainaspects of the invention.

Moreover, not only does the use of reinforcing elements secured to ashipping d1um end member serve to inhbit harmonic oscillations, tofacilitate stacking and to prevent puncture and/or denting, but, as anet efiect, it enables shipping drums to be constructed of a thinnergauge metal With a substantial reduction in the initial expense ofmanufacture and a further reduction in the amount of dead weight thatmust be shpped. With the use of reinforcing elements of this nature,metal gauges as thin as 24- gauge in the case of a fifty-five gallondrum become practica1.

In our copending application Serial No. 807,517 filed August 20, 1959,now abandoned, a novel method of forming reinforcing cups from scrap andapplying them to the end member of a shipping drum has been disclosed.Reinforcing elements used in the i1st embodirnent of the presentinvention may ideally be formed using the method disclosed in theaforesaid copending application.

It will be understood that our novel reinforcing means is not restrictedto use With a perfectly flat end member, but rather will provide similaroscillation inhibiting characteristics, and is equally applicable whenused With shipping drums having generally flat, i.e., slightly concaveor convex end members, and it is this latter meaning which is intendedin the following claims.

We claim as our invention:

1. A reinforcing member for use With shipping drums having a flat endmember that is subjected to drum-head harmonic oscillations duringtransport, said reinforcing member comprising an extensive flangedsupport element having a channel-shaped cross section, said supportelement having its =flanges rigidly secured to said flat end member inface-to-face contact over a substantial area of the 1atter so that saiddrum-head harmonie osciiiatons will be dampened.

2. In combination with a shipping drum having a substantially flat endmember that is subjected to drum-bead harmonie oscillations duringtransport, reinforcing means comprising at least one extensive flangedsupport element of channel-shaped cross secton, said support elementrgid1y secured to said end member over a substantial area of the latterand having its flanges in face-to-face contact therewith so that saidend member will be maintained in a substantially unflexed, relativelyflat condition.

3. In a shippng drum, a drum wall, an end member in the form of a diskhaving a11 upstanding bead portion at its periphery defining a channelfor engaging the drum wal1 and the upstanding bead portion furthersurrounding and defining a flat central portion, flanged reinforcingmeans rigidly secured to the fiat central portion of said disk andoverlying a substantial portion of the area thereof with the flange inface-toface contact with the disk so that harmonie drum-headoscillations in said end member are substantially minimized duringtransport and so that the flat central portion of said disk ismaintained in a substantally unflexed condition.

4. In a shipping drum, a drum wall, an end mernber in the form of a diskhaving an upstanding bead portion at its periphery defining =a channelfor engagng the drum wa1l and with the upstandng bead portion furthersurroundng and defining a flat central portion, flanged reinforcingmeans rigidly secured in face-to-face contact to the fiat centralportion of said disk over a substantial area of the 1atter, saidreinforcing means having a height substantially equal to the height ofsaid upstanding bead portion so that said upstanding bead portion andsaid reinforcing means define a substantially flush supporting surfaceand the flat central portion of said disk is restrained from harmonieoscillations during transport.

5. In a shipping drum, a drum wall, an end member in the form of a diskhaving an upstanding bead portion at its periphery defining a channelfor engaging the drum wall and the upstanding bead portion furthersurrounding and defining a flat central portion, reinforcing meanssecured to the flat central portion of said disk for minimizing harmonicdrum bead oscillations, said reinforcing means comprising a plurality offianged support elements spaced from one another and having asubstantially channel-shaped cross secton, said support eiements havingtheir flanges Welded to the flat central portion of said disk to form aplurality of box-like protrusions on the latter, each of said supportelements defining with said disk a doub1e bottom for protecting said endmember against deformaton when the drum is placed on an irregularsurface.

6. In a shipping drum, a drum wall, an end member in the form of a diskhaving an opstanding bead portion at its periphery defining a channelfor engaging the drum wa11 and the upstanding bead portion furthersurroundng and defining a flat central portion, reinforcing meanssecured to the flat central portion of said disk comprising at least oneholiow support element having a substantally channeI-shaped crosssection and having flanges in face-tmface contact with and welded to asubstantial portion of the area of the disk for minimizing harmoniedrum-bead oscillations, said support element further having a heightsubstantially equal to the height of the said upstanding bead portion sothat said upstanding bead portion and said support element define asubstantially flush supporting surface for protecting said end memberagainst deformation when the drum is placed on an irregular surface.

7. In a shipping drum, a drum wa1l, an end member in the form of a diskhavng an upstanding bead portion at its periphery defining a channel forengaging the drum walt and the upstanding bead portion furthersurrounding and definng a fiat central portion, oscillation inhibitngmeans secured to the fiat central portion of said disk for minimizingharmonic drum-head oscillations, said inhibiting means comprising apiurality of flanged metal cups secured at spaced points in a twodimensional pattern on said central portion and covering a substantialportion of the area of the latter, said cups havng their flanges inface-to-face contact with the metal of said disk and welded to the diskand said cups substantially equal to the height of the upstanding beadportion so as to form with said bead portion a substantially flushsupporting surface for protecting (the end member against deformationwhen the drum is supported on an irregular surface.

References Cited in the file of this patent UNITED STATES PATENTS1,453,508 King May 1, 1923 1,715,782 Pickop June 4, 1929 2,730265Lundgren Jan. 10, 1956 FOREIGN PATENTS 262,483 Italy Jan. 31, 1929

1. A REINFORCING MEMBER FOR USE WITH SHIPPING DRUMS HAVING A FLAT ENDMEMBER THAT IS SUBJECTED TO DRUM-HEAD HARMONIC OSCILLATIONS DURINGTRANSPORT, SAID REINFORCING MEMBER COMPRISING AN EXTENSIVE FLANGEDSUPPORT ELEMENT HAVING A CHANNEL-SHAPED CROSS SECTION, SAID SUPPORTELEMENT HAVING ITS FLANGES RIGIDLY SECURED TO SAID FLAT END MEMBER INFACE-TO-FACE CONTACT OVER A SUBSTANTIAL AREA OF THE LATTER SO THAT SAIDDRUM-HEAD HARMONIC OSCILLATIONS WILL BE DAMPENED.